Fluid compressor



April 18, 1939. P. CRITTENDEN 2,155,257

FLUID COMPRESSOR Original Filed Jan. '51, 1935 sqsoasesr w l 48 3 5! 4664 If; 7 I4 65 I5 I, l "I, 5 E '1 I,

26 m l 24 27 I6 I INVENTOR PHILIP L.CRITTENDEN ATTORN EY Patented Apr.18, 1939 A UNITED STATES PATENT OFFICE FLUID COMPRESSOR Originalapplication January 31, 1935, Serial No. 4,263. Divided and thisapplication March 13, 1937, Serial No. 130,730

5 Claims.

This invention relates to a fluid compressor.

and particularly to an improved compressor having'fluid pressureoperated unloading means associated with the inlet valves thereof.

This application is a division of my application Serial No. 4,263, filedJanuary 31, 1935.

It is an object of this invention to provide an improved fluidcompressor having fluid pressure operated unloading means associatedwith the inlet valves thereof, the unloading means being constructed sothat the inlet valves may be easily removed and replaced when desired.

A further object of the invention is to provide a fluid compressor ofthe type described and in which the unloading means is arranged so thatit may be removed without disconnecting any of the pipe connectionsthrough which fluid under pressure is supplied to the unloading means.

A further object of the invention is to provide an improved fluidcompressor.

Other objects of the invention and features of novelty will be apparentfrom the following description, taken in connection with theaccompanying drawing, in which- Fig. 1 is a fragmentary elevational viewof a compressor embodying this invention, and

Fig. 2 is an enlarged sectional view taken substantially along the line2-2 of Fig. 1.

Referring to the drawing, the compressor therein illustrated has acylinder body I having bores 3 and 4 therein, which are adapted toreceive pistons, not shown. The body I has detachably secured thereto acylinder head 5 which has formed therein above each of the compressorcylinders an exhaust chamber 1 and an inlet chamber 8.

The exhaust chamber 1 is connected by way of a manifold, not shown, to adischarge pipe, not shown, and contains an exhaust valve assemblyindicated generally by the reference numeral III, which may be of anysuitable well known construction. This chamber is closed by means of acover plate l2 which is detachably secured to the head 5 by means ofbolts 4.

The inlet chamber 8 has mounted therein an inlet valve assemblyindicated generally by the reference numeral |5 which serves to controlcommunication between the inlet chamber and the compression chamberindicated at'|6 formed at the upper face of a piston mounted in the bore3. The inlet chamber 8 is open to the atmosphere by way of a manifold,not shown, while one side of the chamber 8 opens on the upper face ofthe cylinder head 5.

The inlet valve assembly |5 comprises a spring cage which is adapted toseat upon an annular seat indicated at I9 surrounding a passage betweenthe inlet chamber 8 and the compression chamber 6.

The inlet valve assembly l5 includes a valve seat member 2| having aplurality of ports 22 and 23 extending therethrough. A pair of annularvalve elements 24 and 25 are adapted to engage a face on the seat member2| to control communication through the ports 22 and 23. The valveelements 24 and 25 are yieldingly pressed into engagement with seats onthe seat member 2| by means of coil springs 21 and 28 which extendbetween the valve elements and the spring cage 20.

The spring cage 26 and valve seat member 2| are detachably securedtogether by means of screws 30, one of which is shown in the drawing.

The spring cage 20 and the valve seat member 2| are held in position bymeans of a spider or frame work indicated generally by the referencenumeral 32 and comprising an annular peripheral portion 33, and aplurality of arms 34 which extend upwardly and inwardly from theperipheral portion 33 and merge into a central portion 35 having a boretherein which is open at the lower end.

A piston 36 is mounted in the bore in the central portion 35 and hassecured to thelower face thereof a plurality of fingers 38 and 39 whichextend into the ports 22 and 23, respectively, to

engage the valve elements 24 and 25 to press them away from their seatson the seat member 2| against the springs 21 and 28.

A spring 48 is positioned between the piston 36 and the valve seatmember 2| and normally urges the piston 36 upwardly so that the fingers38 and 39 do not engage the valve elements 24 and 25, thereby permittingthese valve elements to be held in their seated positions by the springs21 and 28.

The upper end of the bore in the central portion 35 is closed by meansof a wall 45 having an annular gasket 46 mounted in a recess in theexposed face thereof. The gasket 46 is formed of a suitable resilientmaterial such as molded rubber. A passage 41 extends through the wall 45at a. point inwardly of the gasket 46 and communicates with theoperating chamber 48 at the upper face of the piston 36.

The open face of the inlet chamber 8 is closed by means of a cover plate58 which is held in position by means of bolts 5|. The cover plate 56has an adjusting screw 52 associated therewith and adapted to engage thewall 45 of the spider or frame work 32 to press the frame work 82downwardly to hold the valve seat member 2i and the spring cage 28firmly in position. A look nut 58 is secured on the adjusting screw 52to maintain it in the adjusted position.

The cover plate 58, the gasket 45 and the other portions of thecompressor are arranged so that when the cover plate is.in position onthe cylinder head 5, the lower face of the cover plate is engaged by thegasket 45, while the gasket is firmly compressed so that fluid underpressure cannot escape from the chamber between the cover plate 50 andthe wall 45 within the gasket 45.

The cylinder head 5 has a supply passage indicated at 55 formed thereinand connected by way of a pipe 55 with a suitable source of fluid underpressure, not shown.

The cover plate 55 has a passage indicated at 58 formed therein which isadapted, when the cover plate is in position on the cylinder head 5, toestablish communication between the supply passage 55 and the area.within the angular gasket 45. A bushing, indicated at 59, extends acrossthe joint between the cover plate 50 and the cylinder head 5, andhas apassage therethrough connecting the passages 55 and 58. The bushing 59is adapted to be received by recesses in the confronting faces of thecover plate 55 and the cylinder head 5, and serves to prevent leakage offluid under pressure through the joint between these members, and toalso insure that the cover plate 50 will be secured to the cylinder head5 with the passage 58 in communication with the passage 55 in thecylinder head.

In operation, the spring 40 normally maintains the piston 35 and thefingers 38 and 39 in the position in which they are shown in the drawingso as to permit the valve elements 24 and 25 to be held in the seatedposition by the springs 21 and 28, respectively, to thereby load thecompressor.

On the supply of fluid under pressure to the pipe 56, fluid flowsthrough the passage 55 in the cylinder head 5 to the passage 58 in thecover plate 50, thence to the area within the annular gasket 45, andthrough the passage 41 in the wall 45 to the operating chamber 48 at theupper face of the piston 35. Upon an increase in the pressure of fluidin the chamber 48, the piston 36 is moved downwardly against the spring45, while the ends of the flngers 38 and 39 engage the valve elements 24and 25 and move them away from their seats on the seat member 2i againstthe springs 21 and 28 to thereby unload the compressor.

On the subsequent release of fluid under pressure from the pipe 56,fluid is released from the operating chamber 48, and on a reduction inthe pressure of fluid in this chamber, the spring 48 moves the fingers38 and 39 and the piston 36 upwardly so that the valve elements 24 and25 are again permitted to engage their seats to load the compressor.

The compressor provided by this invention i so constructed and arrangedthat it is possible to remove the inlet valve assembly when desiredwithout detaching any of the pipe connections leading to the operatingchamber of the unloading means associated with the valve assembly.

In order to remove the inlet valve assembly l5 it is necessary only toremove the cover plate 50, and the inlet valve assembly may then belifted out through the opening uncovered by the cover plate.

ger that the joints in the pipe connections will,

be loosened or that leaks will develop in these joints. In addition, itwill be seen that this construction permits all of the pipes associatedwith the unloading means to be located at the side of the cylinder head,and does not require them to extend over the top of thecylinder head orthe cover plates of the inlet chambers where they might interfere withthe installation and removal of the inlet valve assemblies.

While one embodiment of the improved compressor construction provided bythis invention has been illustrated and described in detail, it shouldbe understood that the invention is not limited to these details ofconstruction, and that numerous changes and modifications may be madewithout departing from the scope of the following claims.

Having now described .my invention, what I claim as new and desire tosecure by Letters Paten is:

i. In a fluid compressor, in combination, a body having a bore thereinproviding a compression chamber, said body having an inlet chamberassociated therewith and opening on a face thereof, an inlet valveassembly mounted in said inlet chamber and controlling communicationbetween said inlet and compression chambers, said valve assemblyincluding a frame having a valve seat member associated therewith, avalve adapted to seat on said seat member, biasing means yieldinglyurging said valve into engagement with its seat, the frame having anoperating chamber associated therewith, a movable abutment subject tothe pressure of the fluid in said operating chamber and controllingmeans for holding said valve away from its seat against said biasingmeans, a clamp detachably secured to said body and engageable with aportion of said frame to secure said valve assembly in position in saidinlet chamber, the body having a supply passage formed therein throughwhich fluid may be supplied to and released from said operating chamber,the clamp having a passage formed therein and operative when the clampis in position on said body to establish communication between saidsupply passage and said operating chamber, the adjacent ends of thesupply passage in the body and of the passage in the clamp beingenlarged, and a tubular member positioned in said enlarged passageportions and extending across the joint between the body and the clamp.

2. In a fluid compressor, in combination, a body having a bore thereinproviding a compression chamber, said body having an inlet chamberassociated therewith and opening on a face thereof, an inlet valveassembly mounted in said inlet chamber and controlling communicationbetween said inlet and compression chambers, said valve assemblyincluding a frame having a valve seat member associated therewith, avalve adapted to seat on said seat member, biasing means yieldinglyurging said valve into engagement with its seat, the frame havinganoperating chamber associated therewith, a movable I -fluid may besupplied to and released from said operating chamber, the frame of thevalve assembly having an annular gasket associated therewith and adaptedto be engaged by a face of said clamp, the area within said gasketcommunicating with said operating chamber, the clamp having a passageformed therein which is operative when the clamp is in position on saidbody to establish communication between said supply passage and the areawithin said gasket, the adjacent endsof the supply passage in the bodyand of the passage in the clamp being enlarged, and a tubular memberpositioned in said enlarged passage portions and extending across thejoint between the body and the clamp.

3. In a fluid compressor, in combination, a body'having a bore thereinproviding a compression chamber, the body having an inlet chamberassociated therewith and having mounted therein an inlet valve assemblycontrolling communication between said inlet and compression chambers,said body having an opening formed therein through which the valveassembly may be installed and removed from said inlet chamber, the valveassembly comprising a frame having a valve seat member associatedtherewith, a valve adapted to seat on said seat member, biasing meansyieldingly urging said valve into engagement with its seat, the framehaving an operating chamber associated therewith, a movable abutmentsubject to the pressure of fluid in said operating chamber andcontrolling means for holding said valve away from its seat against saidbiasing means, and a cover plate-detachably secured to said body andclosing the opening therein, said cover plate having means associatedtherewith and adapted to engage said frame to maintain the valveassembly in position in 'said inlet chamber, the body having a supplypassage formed therein through which fluid may be supplied to andreleased from said operating chamber, the cover plate having a passageformed therein and operative when the cover plate is in position on saidbody to' establish communication-between said supply passage and saidoperating chamber, the adjacent ends of the supply passage in the bodyand of the passage in the cover plate being enlarged, and a tubular.member positioned in said enlarged passage portions and extending acrossthe joint between the body and the cover plate.

4. In a fluid compressor, in combination, a

body having a bore therein providing a compression chamber, the bodyhaving an inlet chamber associated therewith and having mounted thereinan inlet valve assembly controlling communication between said inlet andcompression chambers, said body having an opening formed therein throughwhich the valve assembly may be installed and removed from said inletchamber, the

adapted to seat on said seat member, biasing means yieldingly urgingsaid valve into engagement with its seat, the frame having an operatingchamber associated therewith, a movable abutment subject to the pressureof fluid in said operating chamber and controlling means for holdingsaid valve away from its seat against said biasing means, a cover platedetachably secured to said body and closing the opening therein, saidcover plate having means associated therewith and adapted to engage saidframe to maintain the valve assembly in position in said inlet chamber,the body having a supply passage formed therein through which fluid maybe supplied to and released from said operating chamber, the frame ofthe valve assembly having an annular gasket associated therewith andadapted to be engaged by a face of said cover plate, the area withinsaid gasket communicating with said operating chamher, the cover platehaving a passage formed therein which is operative when the cover plateis in position on said body to establish communication between saidsupply passage and the area within said gasket, the adjacent ends of thesupply passage in the body and of the passage in the cover plate beingenlarged, and a tubular member positioned in said enlarged passageportions and extending across the joint between the body and the coverplate.

5. In a fluid compressor, in combination, a body having a bore thereinproviding a compression chamber, said body having an inlet chamberassociated therewith and having mounted therein an inlet valve assemblycontrolling communication between said inlet and compression chambers,said body also having an opening formed therein through which the valveassembly may be installed and removed from said inlet chamber, the bodyhaving a mounting face thereon surrounding said opening, the valveassembly comprising a frame having a valve seat member associatedtherewith, a valve adapted to seat on said seat member, biasing meansyieldingly urging said valve into engagement with its seat, the framehaving an operating chamber associated therewith, a movable abutmentsubject to the pressure of the fluid in said operating chamber andcontrolling means for holding said valve away'from its seat against saidbiasing means, a cover plate detachably secured against the mountingface on said body and closing the opening therein, said cover platehaving means associated therewith and adapted to'engage said frame tomaintain the valve assembly in position in said inlet chamber, a bodyhaving a supply passage formed therein through the cover plate having apassage formed therein and opening on the face of said cover plateconfronting the mounting face on the body and adapted to register withthe passage in said body, the adjacent ends of said passages beingenlarged, atubular bushing mounted in said enlarged passage portions andextending across the joint between the cover-plate andthe body, and anannular gasket associated with the frame of the valve assembly andadapted to be engaged by the face of said cover plate, the area withinsaid gasket communicating with said operating chamber, the passage inthe cover plate communicating with the area within said gasket when thecover plate is imposition on said body to thereby establishcommunication between said supply passage and said operating chamber.

" PHILIP L. CRI'II'ENDEN.

